JP2007032815A - Power transmitting chain and power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmitting chain which relieves stress concentration produced in a link and keeps the elongation of a chain within an appropriate value, and a power transmission device. <P>SOLUTION: A power transmitting chain 1 is equipped with a plurality of links 11, 21, a plurality of pins 14 and a plurality of interpieces 15. The links 11, 21 are made up of a link 11 with a column of which the elongation is controlled by taking front and rear insertion parts 12, 13 as independent through holes and of a link 21 without a column which is relatively easy to stretch by taking front and rear insertion parts 22, 23 as one through hole. The link 11 with a column and link 21 without a column are mixed on the basis of a predetermined hybrid pattern. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power transmission chain, and more particularly to a power transmission chain suitable for a continuously variable transmission (CVT) of an automobile and a power transmission device using the same.

  As a continuously variable transmission for an automobile, as shown in FIG. 7, a drive pulley (2) provided on the engine side having a fixed sheave (2a) and a movable sheave (2b), a fixed sheave (3b) and a movable sheave (3a) and a driven pulley (3) provided on the drive wheel side and an endless power transmission chain (1) spanned between them, and a movable sheave (2b) (3a) by a hydraulic actuator The chain (1) is clamped with hydraulic pressure by moving it toward and away from the fixed sheave (2a) (3b), and this clamping force makes contact between the pulley (2) (3) and the chain (1). It is known that a load is generated and torque is transmitted by the frictional force of the contact portion.

As a power transmission chain, Patent Document 1 (Japanese Patent Laid-Open No. 8-31725) discloses a plurality of links having front and rear insertion portions through which pins are inserted, a front insertion portion of one link, and a rear insertion portion of another link. A plurality of first pins and a plurality of second pins that connect the links arranged in the chain width direction so that they can be bent in the length direction, and are fixed to the front insertion portion of one link and The first pin movably fitted in the rear insertion portion of the link and the second pin movably fitted in the front insertion portion of one link and fixed to the rear insertion portion of the other link are relatively rolled. Proposals have been made in which the links can be bent in the longitudinal direction by moving in contact with each other.
Japanese Patent Laid-Open No. 8-31725

  In the power transmission chain of Patent Document 1, further reduction in size and weight is desired. However, when the size and weight are reduced in general, the durability of the link tends to decrease. The cause of damage to the link is mainly due to fatigue cutting due to repeated stress. Therefore, as a countermeasure, the link can be easily deformed (easily stretched) so as to relieve the stress generated in the link. Conceivable. However, if the elongation of the link becomes large, the total length of the chain becomes long, and there is a possibility that the speed change performance and drive performance necessary for the chain cannot be maintained.

  An object of the present invention is to provide a power transmission chain and a power transmission device that can alleviate stress concentration generated in a link and can suppress the elongation of the chain to an appropriate value.

  The power transmission chain according to the present invention includes a plurality of links having front and rear insertion portions through which pins are inserted, and links arranged in the chain width direction so that a front insertion portion of one link and a rear insertion portion of another link correspond to each other. A plurality of first pins and a plurality of second pins arranged before and after connecting each other are provided, and the first pin and the second pin are relatively rolled and brought into contact with each other, whereby the links can be bent in the length direction. In the power transmission chain, the plurality of links, the front and rear insertion portions are independent through-holes, and the links with pillars whose elongation is suppressed, and the front and rear insertion portions are one through-hole. And a column-less link that is relatively easy to extend. The column-less link and the column-less link are mixed based on a predetermined mixed pattern.

  The link with columns is formed by forming the front and rear through holes separated from each other in the link, and the front through hole is the front insertion part and the rear through hole is the rear insertion part. It is formed in a link, and the front part of the through hole is a front insertion part, and the rear part of the through hole is a rear insertion part.

  The number of links with pillars and links without pillars can be set freely, and the hybrid pattern is based on the condition that the chain stretch is properly maintained, for example, based on those with pillars. It can be obtained by replacing the links with columns at locations where stress concentration is likely to occur (both ends in the width direction, portions where the number of links per row is small, etc.) with links without columns.

  One of the first pin and the second pin may be press-fitted and fixed to the front and rear insertion portion of the link, and both may not be fixed (movably fitted). Further, the first pin and the second pin may have different cross-sectional shapes or the same shape. Furthermore, the first pin and the second pin may be the same length, both may be in contact with the sheave surface, and may be of different lengths so that only the longer one is in contact with the sheave surface. Also good.

  At least one of the first pin and the second pin comes into contact with the pulley and transmits power by frictional force. In a chain in which one of the pins contacts the pulley, one of the first pin and the second pin is a pin that contacts the pulley when the chain is used in a continuously variable transmission ( The other pin is referred to as a “pin” (hereinafter referred to as an “interpiece”), and the other pin is referred to as an interpiece or strip (hereinafter referred to as “interpiece”).

  For example, the first pin and the second pin are formed in a required curved surface so that either one of the contact surfaces is a flat surface and the other contact surface can be relatively rolled and moved. Moreover, you may make it each contact surface form a required curved surface for the 1st pin and the 2nd pin. In any case, the contact surface shape of each pin is formed in two types (for example, one having a relatively large curvature and one having a relatively small curvature), so that the pins having different trajectories of rolling contact movement are formed. There may be two types of sets. The locus of the contact position between the first pin and the second pin is, for example, a circle involute.

  In this specification, one end side in the length direction of the link is front and the other end side is rear, but this front and rear are for convenience, and the length direction of the link always coincides with the front and rear direction. It doesn't mean that.

  For example, the link is made of spring steel or carbon tool steel. The material of the link is not limited to spring steel or carbon tool steel, and may of course be other steel such as bearing steel. Appropriate steel such as bearing steel is used as the material of the pin.

  When the pin is fixed to the front and rear insertion portion, the pin is fixed to the front and rear insertion portion, for example, by fitting and fixing the inner edge of the insertion portion and the outer peripheral surface of the pin by mechanical press-fitting. It may be a fit or a cold fit. The first pin and the second pin are fitted to one insertion portion so as to face each other in the length direction of the chain, and either one of them is fitted and fixed to the peripheral surface of the insertion portion of the link. This fitting and fixing is preferably performed at the edges (upper and lower edges) of the portion orthogonal to the length direction of the insertion portion. As described above, in the pin fixing type chain by fitting, the stress of the fixing portion becomes high, so that the stress concentration relaxation effect by using the columnless link becomes particularly remarkable.

  In the mixed pattern, for example, all the links corresponding to the width direction are one of a link with a column and a link without a column. In this case, in a chain where the number of links arranged in one row in the width direction is different, the column with a large number of links is a link without a column and the column with a small number of links is a link with a column, thereby suppressing elongation and alleviating stress concentration. And can be easily balanced. Further, the mixed pattern may be one in which the outermost link in the width direction of each column is a link without a column and the other links are links with a column.

  This power transmission chain is manufactured, for example, by holding a required number of pins and interpieces vertically on a table and then press-fitting links one by one or several together. And at the time of link press-fitting, each link can be arranged in a predetermined mixed pattern by alternately press-fitting a proper number of links with pillars and links without pillars.

  In the above power transmission chain, one of the pins (interpiece) is shorter than the other pin (pin), the end surface of the longer pin contacts the conical sheave surface of the pulley of the continuously variable transmission, It is preferable that power is transmitted by the frictional force due to this contact. Each pulley includes a fixed sheave having a conical sheave surface and a movable sheave having a conical sheave surface facing the sheave surface of the fixed sheave. The chain is sandwiched between the sheave surfaces of both sheaves, and the movable sheave. Is moved by a hydraulic actuator, the distance between sheave surfaces of the continuously variable transmission, that is, the wrapping radius of the chain is changed, and a continuously variable transmission can be performed with a smooth movement.

  The power transmission device according to the present invention includes a first pulley having a conical sheave surface, a second pulley having a conical sheave surface, and power transmission spanned between the first and second pulleys. And a power transmission chain as described in any of the above.

  This power transmission device is suitable for use as a continuously variable transmission of an automobile.

  According to the power transmission chain and the power transmission device of the present invention, the link with columns and the link without columns are mixed, so that the links without columns are all compared to those formed with links with columns. The stress concentration is eased by the amount easily stretched. Further, since the extension of the entire length of the chain can be suppressed as compared with the case where all the links are not provided with a pillar, it is possible to avoid a reduction in transmission performance and driving performance necessary for the chain. Thus, the durability can be improved without changing the outline shape of the link and without deteriorating other performance.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the top and bottom refer to the top and bottom of FIG.

  1 and 2 show a part of a power transmission chain according to the present invention. The power transmission chain (1) has front and rear insertion parts (12) (13) provided at predetermined intervals in the chain length direction. ) (22) (23) having a plurality of links (11) (21) and a plurality of pins (first pins) for connecting the links (11) (21) arranged in the chain width direction so that they can be bent in the length direction ) (14) and an interpiece (second pin) (15).

  For the links (11) and (21), the front and rear insertion portions (12) and (13) are each provided with a pillar link (11) that is an independent through hole, and the front and rear insertion portions (22) and (23) are communication portions ( 24) Two types of links without pillars (21) connected as one through hole are used, and these links with pillars (11) and links without pillars (21) have a predetermined mixed pattern. Are mixed based on.

  As shown in FIG. 3, the front insertion part (12) of the link with pillar (11) includes a pin fixing part (12a) to which a pin (14) (shown by a solid line) is fixed and an interpiece (15) (two points). Inter-piece movable part (12b) that can be movably fitted (indicated by the chain line), and the rear insertion part (13) is a pin movable part to which the pin (14) (indicated by a two-dot chain line) is movably fitted (13a) and an interpiece (15) (shown by a solid line) are fixed to an interpiece fixing portion (13b).

  Similarly, as shown in FIG. 4, the front insertion portion (22) of the postless link (21) includes a pin fixing portion (22a) and an interpiece (15) to which the pin (14) (shown by a solid line) is fixed. Interposer movable part (22b) that can be movably fitted (indicated by a two-dot chain line), and rear insertion part (23) is movably fitted to pin (14) (indicated by a two-dot chain line) The pin movable portion (23a) and the interpiece (15) (shown by a solid line) are composed of an interpiece fixing portion (23b). The shape of the front insertion part (22) and rear insertion part (23) of the link without pillar (21) is the same shape as the front insertion part (12) and rear insertion part (13) of the link with pillar (11). Yes.

  Therefore, the only difference between the pillared link (11) and the pillarless link (21) is the presence or absence of the communication part (24), and the outline contour shape and each insertion part (12) (13) (22) (23 ) Have the same shape. Due to the presence or absence of the communication portion (24), the link with the pillar (11) is relatively restrained from being stretched, and the link without the pillar (21) is relatively easy to stretch.

  In this power transmission chain (1), the necessary number of pins (14) and interpiece (15) are held vertically on the table, and then the links (11) and (21) are press-fitted one by one. Manufactured by. This press-fitting is performed between the upper and lower edge portions of the pin (14) and the interpiece (15) and the upper and lower edge portions of the pin fixing portion (12a) (22a) and the interpiece fixing portion (13b) (23b). The press-fitting allowance is set to 0.005 mm to 0.1 mm.

  When connecting the links (11) (21) arranged in the chain width direction, the front insertion part (12) (22) of one link (11) (21) and the rear insertion of the other link (11) (21) The links (11) and (21) are overlapped so that the sections (13) and (23) correspond to each other, and the pin (14) is connected to the front insertion section (12) and (22) of one link (11) and (21). It is fixed and movably fitted to the rear insertion portions (13) and (23) of the other links (11) and (21), and the interpiece (15) is inserted into the front insertion portion of the one link (11) and (21) ( 12) It is fitted to (22) so as to be movable and is fixed to the rear insertion parts (13), (23) of the other links (11), (21). Then, the pin (14) and the interpiece (15) are relatively rolled and brought into contact with each other, whereby the links (11) and (21) can be bent in the length direction (front-rear direction). The locus of the contact position between the pin (14) and the interpiece (15) relative to the pin (14) is an involute of the circle.In this embodiment, the contact surface (14a) of the pin (14) is The cross section has an involute shape having a basic circle with a radius Rb and a center M, and the contact surface (15a) of the interpiece (15) is a flat surface (the cross-sectional shape is a straight line). Thus, when each link (11) (21) moves from the straight part of the chain (1) to the arc part or from the arc part to the straight part, the front insertion part (12) (22) 15) Rolling contact (slightly sliding contact) of the contact surface (15a) with the contact surface (14a) of the pin (14) against the pin (14) fixed in the interpiece movable part (12b) (22b) In the rear insertion part (13) (23), the contact surface (14a) is in contact with the interpiece (15) with respect to the interpiece (15) in which the pin (14) is fixed. It moves in the pin movable part (13a) while rolling (including a slight sliding contact) on the surface (15a). 3 and 4, the portions indicated by reference signs A and B are lines (points in the cross section) where the pin (14) and the interpiece (15) are in contact with each other in the straight portion of the chain (1). , AB is the pitch.

  Since the shape of the front and rear insertion parts (22) and (23) of the pillarless link (21) is the same as the front and rear insertion parts (12) and (13) of the pillared link (11), the link with pillars (11) It is possible to freely set the position of the pillar-less link (21) in the chain (1).

  In the example shown in FIG. 1, all the links (one row) corresponding to the width direction of the chain (1) are either a link with a column (11) or a link without a column (21). Although not shown in the figure, the links with pillars (11) and the links without pillars (21) may be alternately arranged in one row. Even if only one of the link with column (11) or the link without column (21) is used in one column, the link with column (11) and link without column (21) are mixed in one column In either case, the number of links with pillars (11) and the number of links without pillars (21) need not be the same, and the number of both is determined in terms of the balance between suppression of elongation and relaxation of stress concentration.

  FIG. 5 shows another example of the mixed pattern. In FIG. 5, the outermost link in the width direction of each row is a columnless link (21), and the other links are columned links (11). The links (21) arranged at both ends of the chain (1) receive a relatively large force, and since this link (21) is made without a column, the stress concentration on the chain (1) Is effectively mitigated.

  This power transmission chain (1) is used in the CVT shown in FIG. 6. At this time, for example, the interpiece (second pin) (15) is made shorter than the pin (first pin) (14). The end surface of the pin (14) is not in contact with the conical sheave surfaces (2c) and (2d) of the fixed sheave (2a) and the movable sheave (2b) of the pulley (2). Contact is made with the conical sheave surfaces (2c) and (2d) of the pulley (2), and power is transmitted by the frictional force caused by the contact. As described above, since the pin (14) and the interpiece (15) are in rolling contact, the pin (14) hardly rotates relative to the sheave surfaces (2c) (2d) of the pulley (2). Thus, friction loss is reduced and a high power transmission rate is secured.

  The structure in which the link with pillar (11) and the link without pillar (21) are mixed is also applicable to a chain in which the lengths of the first pin and the second pin are substantially equal and both are in contact with the sheave surface. Furthermore, the present invention can be applied to a chain in which both the first pin and the second pin are movably fitted to the front and rear insertion portions and various other types of power transmission chains.

FIG. 1 is a plan view showing a part of a first embodiment of a power transmission chain according to the present invention. FIG. 2 is an enlarged perspective view of the same. FIG. 3 is an enlarged side view of the link with pillars. FIG. 4 is an enlarged side view of the pillarless link. FIG. 5 is a plan view showing a part of a second embodiment of the power transmission chain according to the present invention. FIG. 6 is a front view showing a state in which the power transmission chain is attached to the pulley. FIG. 7 is a perspective view showing an example of a continuously variable transmission in which the power transmission chain according to the present invention is used.

Explanation of symbols

(1) Power transmission chain
(2) (3) Pulley
(2a) (3a) Fixed sheave
(2b) (3b) Movable sheave
(2c) (2d) Conical sheave surface
(11) Link with pillar
(12) Front insertion part
(13) Rear insertion part
(14) Pin (1st pin)
(15) Interpiece (2nd pin)
(21) Pillarless link
(22) Front insertion part
(23) Rear insertion part

Claims (5)

A plurality of links having front and rear insertion portions through which pins are inserted, and a plurality of links arranged before and after connecting links aligned in the chain width direction so that a front insertion portion of one link and a rear insertion portion of another link correspond to each other. In the power transmission chain provided with the first pin and the plurality of second pins, the first pin and the second pin are relatively in rolling contact with each other, so that the links can be bent in the longitudinal direction.
The plurality of links include a link with a pillar whose extension is suppressed by the front and rear insertion portions being independent through holes, and a column that is relatively easily extended by the front and rear insertion portion being a single through hole. A power transmission chain comprising a link without a link, wherein a link with a column and a link without a column are mixed based on a predetermined mixed pattern.   2. The power transmission chain according to claim 1, wherein the mixed pattern is such that all the links corresponding to the width direction are either links with columns or links without columns.   The power transmission chain according to claim 1, wherein the mixed pattern is such that the outermost link in the width direction of each row is a link without a column and the other links are links with a column.   One of the first pin and the second pin is fixed to the front insertion portion of one link and is movably fitted to the rear insertion portion of the other link, and the other is the front insertion portion of the one link. The power transmission chain according to any one of claims 1 to 3, wherein the power transmission chain is movably fitted to the rear and fixed to a rear insertion portion of another link.   A power transmission chain comprising: a first pulley having a conical surface sheave surface; a second pulley having a conical surface sheave surface; and a power transmission chain spanned between the first and second pulleys. A power transmission device according to claim 1.

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